邻二甲苯选择性氯化的研究

Selective Chlorination of o - Xylene

以FeCl_3为主催化剂,噻蒽化合物为助催化剂,对邻二甲苯选择性氯化进行了研究,获得较高的4-氯代邻二甲苯选择性,并探讨了催化机理。考察了反应时间、反应温度、催化剂用量、氯气流速对反应的影响,确定了最佳反应条件:反应温度0℃,通氯速度0.16 mol/h,反应时间8 h,FeCl_3用量0.1％,助催化剂用量0.2％。此条件下,4-氯代邻二甲苯与3-氯代邻二甲苯的比例为3.313。

The selective chlorination of o - xylene using FeCl3 as catalyst and thianthrene compound as cocatalyst was studied. The catalyst was more selective than Lewis acid catalyst. Mechanism of catalysis of thianthrene compounds was discussed. The effects of reaction temperature, flow rate of chlorine, amount of catalyst on reaction were investigated. The optimum comditions were determined as follows: reaction temperature 0 ℃ , flow rate of chlorine 0.16mol/h, reaction time 8 h, amount of FeCl3 0.1%, and amount of cocatalyst 0.2%. The ratio of 4 - chloro -o - xylene to 3 - chloro - o - xylene was 3.313 in the above reaction.